---
id: "CVE-2026-121393"
kind: "vulnerability"
aliases: ["CVE-2026-121393"]
title: "FreeRDP: crafted RemoteFX rectangles crash RDP clients built with verbose assertions"
severity: "high"
cvss: 7.1
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["c", "freerdp", "package", "rdp", "remote-desktop"]
not_affected_if: ["default-build-config", "trusted-servers-only"]
published_at: "2026-11-03T15:17:26+00:00"
first_seen_at: "2026-11-03T15:21:57+00:00"
updated_at: "2026-11-03T15:23:06+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121393", "first_seen_at": "2026-11-03T15:21:57+00:00"}]
---

# FreeRDP: crafted RemoteFX rectangles crash RDP clients built with verbose assertions

FreeRDP from 3.0.0 before 3.32.2 lets a malicious RDP server send crafted RemoteFX region rectangles that trigger a 16-bit coordinate assertion in rfx_process_message. The assertion terminates the client process, causing a denial of service.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the FreeRDP version installed on client machines or in the application's dependencies, for example with `xfreerdp --version`.
- Confirm whether the build uses verbose WinPR assertions, which the sources say is required for the crash.

## Fix

- FreeRDP: move to `3.32.2` or later, per the NVD range.

## Timeline

- 2026-11-03T15:21:57+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121393

## Documents

- [advisory] Vendor advisory: github.com https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-7qw2-8h66-pvpw
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/freerdp-3.0.0-before-3.32.2-denial-of-service-via-remotefx-region-assertion

## From the sources

FreeRDP from 3.0.0 before 3.32.2 contains a denial of service vulnerability that allows malicious RDP servers to abort clients built with verbose WinPR assertions by sending crafted RemoteFX region rectangles. Attackers can supply a rectangle with x set to 65535 alongside a SurfaceBits destination left of 1, triggering a 16-bit coordinate assertion in rfx_process_message that terminates the client process.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_